High-frequency high-power voltage-controlled oscillator based on GaN HEMT and control method

Abstract

The invention discloses a GaN HEMT-based high-frequency high-power voltage-controlled oscillator and a control method. The oscillator comprises an oscillation loop, a variable resistance circuit, a matching circuit, a balun circuit, a frequency doubler circuit and an output matching network circuit. The method comprises the following steps: adjusting the frequency of an oscillation signal to obtain an adjusted oscillation signal; the power loss of the adjusted oscillation signal is reduced; performing conversion processing on the low-power-loss single-end oscillation signal to obtain a double-end output differential signal; carrying out addition processing on the differential signals output from the two ends to obtain oscillation signals of second harmonics; the loss from the oscillation signal of the second harmonic to the output load is reduced, and a high-frequency and high-power oscillation signal is obtained. The high-frequency and high-output-power voltage-controlled oscillator can be realized under the condition that a variable capacitance diode is not used. The high-frequency and high-power voltage-controlled oscillator based on the GaN HEMT and the control method can be widely applied to the technical field of radio frequency integrated circuits.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency integrated circuits, and in particular to a high-frequency and high-power voltage-controlled oscillator based on GaN HEMT and a control method thereof. Background Art

[0002] The voltage-controlled oscillator (VCO) is a key component in wireless communication systems, used to generate variable-frequency oscillation signals. The voltage-controlled oscillator must have a certain output power to drive the next-level circuit, especially in millimeter-wave communication array antennas and active phased array radars, where the output power of the voltage-controlled oscillator is required to be higher. In the past, the output power of the voltage-controlled oscillator based on CMOS devices was not high, which was due to the device itself. Therefore, the voltage-controlled oscillator needs to be connected to a power amplifier module, which undoubtedly increases system noise, module complexity, design complexity and product cost.

[0003] GaNHEMT is a typical device of the third generation of semiconductors. It has high output power and good noise characteristics at high frequencies, making it very suitable for the design of voltage-controlled oscillators. However, due to the lack of varactor devices under the current mature GaNHEMT process, the frequency tuning range of the voltage-controlled oscillator is very small. In addition, the application frequency of voltage-controlled oscillators continues to increase, and varactor diodes are indispensable in traditional high-frequency voltage-controlled oscillators. In related technologies, GaNHEMT is often transformed into a varactor diode, but at high frequencies, its effect is very limited, and some current GaNHEMT processes no longer support the transformation of GaNHEMT into a varactor diode. Therefore, varactor diodes cannot be used in voltage-controlled oscillators under the GaNHEMT process, making it difficult to output high-frequency oscillation signals. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a high-frequency and high-power voltage-controlled oscillator and a control method based on GaN HEMT, which can realize a high-frequency and high-output power voltage-controlled oscillator without using a varactor diode.

[0005] The first technical solution adopted by the present invention is: a high-frequency and high-power voltage-controlled oscillator based on GaN HEMT, comprising an oscillation circuit, a variable resistance circuit, a matching circuit, a balun circuit, a frequency doubler circuit and an output matching network circuit, wherein the oscillation circuit, the variable resistance circuit, the matching circuit, the balun circuit, the frequency doubler circuit and the output matching network circuit are connected in sequence, wherein:

[0006] The oscillation circuit is used to generate an oscillation signal;

[0007] The variable resistance circuit is used to adjust the frequency of the oscillation signal to obtain an adjusted oscillation signal;

[0008] The matching circuit is used to reduce the power loss of the adjusted oscillation signal to the next-stage balun circuit to obtain a single-ended oscillation signal with low power loss;

[0009] The balun circuit is used to convert the low-power-loss single-ended oscillation signal to obtain a differential signal output at both ends;

[0010] The frequency doubler circuit is used to perform addition processing on the differential signal output from both ends to obtain a second harmonic oscillation signal;

[0011] The output matching network circuit is used to reduce the loss of the second harmonic oscillation signal to the output load, thereby obtaining a high-frequency and high-power oscillation signal.

[0012] Further, the oscillation circuit specifically includes a first GaN HEMT transistor, a first capacitor, a second capacitor, a first inductor, a second inductor and a first voltage source, wherein the gate of the first GaN HEMT transistor, the first end of the first capacitor and the first end of the second inductor are connected, the second end of the second inductor and the first end of the second capacitor are connected to the positive terminal of the first voltage source, the second end of the first capacitor, the drain of the first GaN HEMT transistor and the second end of the first inductor are connected to the variable resistance circuit, the first end of the first inductor is connected to a high level, and the source of the first GaN HEMT transistor, the second end of the second capacitor and the negative terminal of the first voltage source are all grounded.

[0013] Further, the variable resistance circuit specifically includes a third capacitor, a second GaN HEMT transistor, a third GaN HEMT transistor, a third inductor, a fourth inductor, a fifth inductor, a second voltage source, a third voltage source and a fourth voltage source, wherein a first end of the third capacitor is connected to the oscillation circuit, a second end of the third capacitor, a drain of the second GaN HEMT transistor, a drain of the third GaN HEMT transistor, and a first end of the fifth inductor are connected to the matching circuit, a gate of the second GaN HEMT transistor is connected to a second end of the fourth inductor, a first end of the fourth inductor is connected to a positive end of the third voltage source, a gate of the third GaN HEMT transistor is connected to a first end of the third inductor, a second end of the third inductor is connected to a positive end of the second voltage source, a second end of the fifth inductor is connected to a positive end of the fourth voltage source, and a negative end of the second voltage source, a negative end of the third voltage source, a negative end of the fourth voltage source, a source of the second GaN HEMT transistor and a source of the third GaN HEMT transistor are all grounded.

[0014] Furthermore, the matching circuit specifically includes a fourth capacitor and a fifth capacitor, wherein a first end of the fourth capacitor is connected to the variable resistance circuit, a second end of the fourth capacitor and a second end of the fifth capacitor are connected to the balun circuit, and a first end of the fifth capacitor is grounded.

[0015] Furthermore, the balun circuit specifically includes a first coil and a second coil, wherein the first coil and the second coil are anti-coupled, the first end of the first coil is connected to the matching circuit, the second end of the first coil is grounded, and the first end of the second coil and the second end of the second coil are both connected to the doubler circuit.

[0016] Further, the doubler circuit specifically includes a fourth GaN HEMT transistor, a fifth GaN HEMT transistor, a sixth inductor, a seventh inductor, a fifth voltage source and a sixth voltage source, wherein the gate of the fourth GaN HEMT transistor and the first end of the sixth inductor are connected to the balun circuit, the second end of the sixth inductor is connected to the positive terminal of the fifth voltage source, the gate of the fifth GaN HEMT transistor and the first end of the seventh inductor are connected to the balun circuit, the second end of the seventh inductor is connected to the positive terminal of the sixth voltage source, the drain of the fourth GaN HEMT transistor and the drain of the fifth GaN HEMT transistor are connected to the output matching network circuit, and the source of the fourth GaN HEMT transistor, the source of the fifth GaN HEMT transistor, the negative terminal of the fifth voltage source and the negative terminal of the sixth voltage source are all grounded.

[0017] Further, the output matching network circuit specifically includes a sixth capacitor, a seventh inductor, an eighth inductor, a first resistor and a seventh voltage source, wherein the first end of the sixth capacitor and the first end of the seventh inductor are connected to the doubler circuit, the second end of the sixth capacitor and the first end of the eighth inductor are connected to the first end of the first resistor, the second end of the seventh inductor is connected to the positive terminal of the seventh voltage source, and the second end of the first resistor, the second end of the eighth inductor and the negative terminal of the seventh voltage source are all grounded.

[0018] The second technical solution adopted by the present invention is: a control method of a high-frequency and high-power voltage-controlled oscillator based on GaN HEMT, comprising the following steps:

[0019] Acquiring an oscillation signal and adjusting the frequency of the oscillation signal to obtain an adjusted oscillation signal;

[0020] Reducing the power loss of the adjusted oscillation signal to obtain a single-ended oscillation signal with low power loss;

[0021] Converting the low-power-loss single-ended oscillation signal to obtain a double-ended output differential signal;

[0022] Adding the differential signals output from both ends to obtain a second harmonic oscillation signal;

[0023] The loss of the second harmonic oscillation signal to the output load is reduced to obtain a high-frequency and high-power oscillation signal.

[0024] The beneficial effects of the method and system of the present invention are as follows: the present invention adjusts the frequency and power of the oscillation signal, realizes the frequency change by using a variable resistor, the variable resistor is realized by a GaN HEMT working in a linear region rather than a saturation region, further uses a balun circuit to convert the adjusted oscillation signal to realize the conversion of a single-ended signal into a differential signal, and then uses a doubler circuit to add the differential signal outputted from both ends to realize the addition of the differential signal, thereby canceling out the fundamental signal, outputting the second harmonic, and realizing a high-frequency oscillation signal, and finally reduces the loss of the second harmonic oscillation signal to the output load through an output matching network circuit, and can realize a high-frequency and high-output power voltage-controlled oscillator without using a varactor diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the circuit principle of a high-frequency and high-power voltage-controlled oscillator based on GaN HEMT of the present invention;

[0026] Figure 2 It is a schematic diagram of the steps of a control method of a high-frequency and high-power voltage-controlled oscillator based on GaN HEMT of the present invention;

[0027] Figure 3 1 is a schematic diagram of the circuit principle of a specific embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the circuit principle of the second specific embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only provided for the convenience of explanation and description, and the order between the steps is not limited in any way. The execution order of each step in the embodiment can be adaptively adjusted according to the understanding of those skilled in the art.

[0030] Reference Figure 1The present invention provides a high-frequency and high-power voltage-controlled oscillator based on GaN HEMT, comprising an oscillation circuit, a variable resistance circuit, a matching circuit, a balun circuit, a frequency doubler circuit and an output matching network circuit, wherein the oscillation circuit, the variable resistance circuit, the matching circuit, the balun circuit, the frequency doubler circuit and the output matching network circuit are connected in sequence, wherein:

[0031] The oscillation circuit is used to generate an oscillation signal;

[0032] Specifically, the oscillation circuit specifically includes a first GaN HEMT transistor M 1 , the first capacitor C 1 , the second capacitor C g2 , the first inductor L d1 , the second inductor L g1 With the first voltage source V g1 , wherein the first GaN HEMT transistor M 1 The gate of the first capacitor C 1 The first end and the second inductor L g1 The first end of the second inductor L g1 The second end of the second capacitor C g2 The first terminal and the first voltage source V g1 The positive terminal of the first capacitor C 1 The second end of the first GaN HEMT transistor M 1 The drain of the first inductor L d1 The second end of the first inductor L is connected to the variable resistance circuit. d1 The first terminal is connected to a high level, and the first GaN HEMT transistor M 1 The source of the second capacitor C g2 The second end is connected to the first voltage source V g1 The negative terminals are grounded.

[0033] In this embodiment, the oscillation circuit includes a GaN HEMT transistor M 1 , capacitor C 1 , capacitor C g2 、Inductance L d1 、Inductance L g1 and voltage source V g1 , GaN HEMT transistor M 1 The drain of d1 Connected to the voltage source AVDD, and through the capacitor C 1 The gate is fed back to the gate through the inductor L g1 and voltage source V g1 Bias, source grounded.

[0034] The variable resistance circuit is used to adjust the frequency of the oscillation signal to obtain an adjusted oscillation signal;

[0035] Specifically, the variable resistance circuit specifically includes a third capacitor C 0 , the second GaN HEMT transistor M 2 , the third GaN HEMT transistor M 3 , the third inductor L g2 , the fourth inductor L g3 、The fifth inductor L ctr1 , the second voltage source V g2 , the third voltage source V g3 With the fourth voltage source V ctr1 , wherein the third capacitor C 0 The first end of the third capacitor C is connected to the oscillation circuit. 0 The second end of the second GaN HEMT transistor M 2 The drain of the third GaN HEMT transistor M 3 The drain of the fifth inductor L ctr1 The first end of the second GaN HEMT transistor M is connected to the matching circuit. 2 The gate and the fourth inductor L g3 The second end of the fourth inductor L g3 The first terminal is connected to the third voltage source V g3 The positive terminal of the third GaN HEMT transistor M 3 The gate and the third inductor L g2 The first end of the third inductor L g2 The second terminal is connected to the second voltage source V g2 The positive terminal of the fifth inductor L ctr1 The second end is connected to the fourth voltage source V ctr1 The positive terminal of the second voltage source V g2 The negative terminal of the third voltage source V g3 The negative terminal of the fourth voltage source V ctr1 The negative terminal of the second GaN HEMT transistor M 2 The source of the third GaN HEMT transistor M 3 The sources are grounded.

[0036] In the embodiment of the present invention, the variable resistor is composed of a capacitor C 0 、GaN HEMT transistor M 2 、GaN HEMT transistor M 3 、Inductance L g2 、Inductance Lg3 、Inductance L ctr1 , voltage source V g2 , voltage source V g3 and voltage source V ctr1 Composition, GaN HEMT transistor M 2 and GaN HEMT transistor M 3 Work in the linear region, not the saturation region. GaN HEMT transistor M 2 and GaN HEMT transistor M 3 The drain is directly connected to the 0 With M 1 connected, and through the inductor L ctr1 and voltage source V ctr1 Connected, V ctr1 Changes in GaN HEMT transistor M can be changed 2 and GaN HEMT transistor M 3 The resistance value of the GaN HEMT transistor M 2 and GaN HEMT transistor M 3 The source of M is grounded. 2 The gate passes through the inductor L g2 and voltage source V g2 Connected, M 3 The gate passes through the inductor L g3 and voltage source V g3 connected.

[0037] The matching circuit is used to reduce the power loss of the adjusted oscillation signal to the next-stage balun circuit to obtain a single-ended oscillation signal with low power loss;

[0038] Specifically, the matching circuit specifically includes a fourth capacitor C 2 With the fifth capacitor C 3 , wherein the fourth capacitor C 2 The first end of the variable resistor circuit is connected to the fourth capacitor C 2 The second end of the fifth capacitor C 3 The second end of the fifth capacitor C is connected to the balun circuit. 3 The first end is grounded.

[0039] In the embodiment of the present invention, the matching circuit is composed of a capacitor C 2 and C 3 Composition. 2 One end is connected to a GaN HEMT transistor M 2 and GaN HEMT transistor M 3 The other end is connected to the balun, C 3 One end is connected to ground and the other end is connected to C 2.

[0040] The balun circuit is used to convert the low-power-loss single-ended oscillation signal to obtain a differential signal output at both ends;

[0041] Specifically, the balun circuit specifically includes a first coil L pri With the second coil L sec , wherein the first coil L pri With the second coil L sec The first coil L is coupled in reverse phase. pri The first end of the first coil L is connected to the matching circuit. pri The second end of the second coil L is grounded. sec The first end of the second coil L sec The second ends of are connected to the doubler circuit.

[0042] In the embodiment of the present invention, the balun is composed of a coil L pri and coil L sec The coil L is composed of two coils and is anti-phase coupled. pri One end is connected to the output end of the matching circuit, and the other end is grounded. sec The two ends are respectively connected to the two ends of the doubler.

[0043] The frequency doubler circuit is used to perform addition processing on the differential signal output from both ends to obtain a second harmonic oscillation signal;

[0044] Specifically, the frequency doubler circuit specifically includes a fourth GaN HEMT transistor M 4 , the fifth GaN HEMT transistor M 5 、The sixth inductor L g4 、Seventh inductor L g5 , the fifth voltage source V g4 With the sixth voltage source V g5 , wherein the fourth GaN HEMT transistor M 4 The gate of the sixth inductor L g4 The first end of the sixth inductor L is connected to the balun circuit. g4 The second end is connected to the fifth voltage source V g4 The positive terminal of the fifth GaN HEMT transistor M 5 The gate of the seventh inductor L g5 The first end of the seventh inductor L is connected to the balun circuit. g5 The second end of the sixth voltage source V g5 The positive terminal of the fourth GaN HEMT transistor M 4 The drain of the fifth GaN HEMT transistor M5 The drain of the fourth GaN HEMT transistor M is connected to the output matching network circuit. 4 The source of the fifth GaN HEMT transistor M 5 The source of the fifth voltage source V g4 The negative terminal of the sixth voltage source V g5 The negative terminals are grounded.

[0045] In the embodiment of the present invention, the frequency doubler is composed of GaN HEMT transistors M 4 、GaN HEMT transistor M 5 、Inductance L g4 、Inductance L g5 , voltage source V g4 and voltage source V g5 Composition. GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The drain is directly connected to the voltage source V mul Power supply, GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The gates of the GaN HEMT transistors M are connected to the two output terminals of the balun. 4 、GaN HEMT transistor M 5 The source of the GaNHEMT transistor M 4 The gate is connected through the inductor L g4 and voltage source V g4 Bias, GaN HEMT transistor M 5 The gate is connected through the inductor L g5 and voltage source V g5 Bias.

[0046] The output matching network circuit is used to reduce the loss of the second harmonic oscillation signal to the output load, thereby obtaining a high-frequency and high-power oscillation signal.

[0047] Specifically, the output matching network circuit specifically includes a sixth capacitor C 4 、Seventh inductor L mul 、The eighth inductor L L , the first resistor R L With the seventh voltage source V mul , wherein the sixth capacitor C 4 The first end of the seventh inductor L mul The first end of the sixth capacitor C is connected to the doubler circuit. 4 The second end of the eighth inductor L L The first end and the first resistor R LThe first end of the seventh inductor L mul The second end of the seventh voltage source V mul The positive terminal of the first resistor R L The second end of the eighth inductor L L The second end of the seventh voltage source V mul The negative terminals are grounded.

[0048] In the embodiment of the present invention, the output matching network is composed of capacitor C 4 、Inductance L L , capacitor C 4 and voltage source V mul Composition. Capacitor C 4 One end is connected to load R L The other end is connected to the GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The drain inductor L mul One end is connected to a GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The other end is connected to the voltage source V mul , capacitor C 4 One end is connected to a GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The drain terminal is connected to ground.

[0049] Reference Figure 2 , a control method of a high-frequency and high-power voltage-controlled oscillator based on GaN HEMT, comprising the following steps:

[0050] S100, acquiring an oscillation signal and adjusting the frequency of the oscillation signal to obtain an adjusted oscillation signal;

[0051] S200, reducing the power loss of the adjusted oscillation signal to obtain a single-ended oscillation signal with low power loss;

[0052] S300, converting the low-power-loss single-ended oscillation signal to obtain a double-ended output differential signal;

[0053] S400, adding the differential signals output from both ends to obtain a second harmonic oscillation signal;

[0054] S500, reducing the loss of the second harmonic oscillation signal to the output load to obtain a high-frequency and high-power oscillation signal.

[0055] In summary, in the embodiment of the present invention, an oscillation signal is first generated by an oscillation circuit and a variable resistor together, and the frequency of the oscillation signal can be changed by the variable resistor. Then, the oscillation signal passes through a balun to obtain a set of fully differential signals. This set of fully differential signals then passes through the gate of the doubler to obtain a signal after the full differential signal is added at the drain. The amplitude of the fundamental frequency of the summed signal has been greatly reduced, and the amplitude of the second harmonic has been enhanced, that is, a signal frequency twice the original oscillation signal frequency is obtained. Finally, the signal passes through an output matching network to reduce the attenuation of the signal power. Finally, a signal frequency twice the original oscillation signal frequency is obtained at the load end, and the power is higher.

[0056] Among them, the oscillation circuit and the variable resistor together generate an oscillation signal, and the variable resistor is used to change the frequency of the oscillation signal to increase the tuning range of the voltage-controlled oscillator; the matching circuit is used to reduce the attenuation of the power of the output signal of the voltage-controlled oscillator to the next-stage circuit, so that the output signal is transmitted to the balun with a larger power; the balun converts the single-ended output signal into a differential signal with a double-ended output, and the differential signals are equal in size and 180° in phase; the doubler adds the differential signals to offset the fundamental signal and double the amplitude of the second harmonic signal; the output matching network is used to reduce the loss of the output signal of the doubler to the load.

[0057] Therefore, the embodiment of the present invention uses a variable resistor to replace the varactor diode, and the variable resistor can be implemented using a GaN HEMT tube working in the linear region, making it possible to design a voltage-controlled oscillator in a GaN HEMT process without a varactor diode. In addition, the embodiment of the present invention achieves a high-frequency oscillation signal output by using a balun and a doubler, and has a lower requirement for the cutoff frequency of the GaNHEMT, which is in line with the current situation that the cutoff frequency of the GaN HEMT is not high under the current GaN HEMT process. Specific embodiment one:

[0059] The invention provides a GaN HEMT high-frequency high-power voltage-controlled oscillator without using a varactor diode, comprising: an oscillation circuit, a variable resistor, a matching circuit, a balun, a frequency doubler and an output matching network.

[0060] The oscillation circuit consists of the GaN HEMT transistor M 1 , capacitor C 1 , capacitor C d1 , capacitor C g1 、Inductance L d1 、Inductance L g1 , voltage source V g1 and voltage source AVDD.

[0061] GaN HEMT transistor M 1 The drain ofd1 Connect to voltage source AVDD and pass capacitor C 1 Feedback to the gate; the gate passes through the inductor L g1 and voltage source V g1 Bias, source grounded; bypass capacitor C d1 One end connected to L d1 , the other end is grounded; bypass capacitor C g1 One end connected to L g1 , and the other end is grounded.

[0062] The variable resistor is composed of capacitor C 0 、GaN HEMT transistor M 2 、GaN HEMT transistor M 3 、GaN HEMT transistor M 31 、Inductance L g2 、Inductance L g3 、Inductance L g31 、Inductance L ctrl , voltage source V g2 , voltage source V g3 , voltage source V g31 and voltage source V ctrl composition.

[0063] GaN HEMT transistor M 2 、GaN HEMT transistor M 3 、GaN HEMT transistor M 31 The source of the GaNHEMT transistor M is grounded. 2 The gate passes through the inductor L g2 and voltage source V g2 Connected, GaN HEMT transistor M 3 The gate passes through the inductor L g3 and voltage source U g3 Connected, GaN HEMT transistor M 31 The gate passes through the inductor L g31 and voltage source V g31 GaNHEMT transistor M 2 、GaN HEMT transistor M 3 、GaN HEMT transistor M 31 The drain terminals of the capacitor C 0 One end is connected to a GaN HEMT transistor M 1 The other end is connected to the drain of GaN HEMT transistor M 2 、GaN HEMT transistor M 3 、GaN HEMT transistor M 31 The drain of the inductor L ctrl One end is connected to a GaN HEMT transistor M2 、GaN HEMT transistor M 3 、GaN HEMT transistor M 31 The other end is connected to the voltage source V ctrl . Bypass capacitor C g2 One end is connected to a voltage source V g3 , the other end is grounded; bypass capacitor C g2 One end connected to L g2 , the other end is grounded; bypass capacitor C g31 One end is connected to a voltage source V g31 ; The other end is grounded, bypass capacitor C ctrl One end is connected to a voltage source V ctrl , and the other end is grounded.

[0064] The matching network consists of capacitor C 2 and inductor L 0 Composition, capacitor C 2 One end is connected to a GaN HEMT transistor M 2 、GaN HEMT transistor M 3 、GaN HEMT transistor M 31 The other end is connected to the inductor L 0 , inductance L 0 The other end is grounded.

[0065] The balun consists of a coil L pri and coil L sec The coil L is composed of two coils and is anti-phase coupled. pri One end is connected to the output end of the matching circuit, and the other end is grounded. sec The two ends are respectively connected to the two ends of the doubler.

[0066] The frequency doubler is composed of GaN HEMT transistor M 4 、GaN HEMT transistor M 5 、Inductance L g4 、Inductance L g5 , voltage source V g4 and voltage source V g5 Composition. GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The drain is directly connected to the voltage source V mul Power supply, GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The gates of the GaN HEMT transistors M are connected to the two output terminals of the balun. 4 、GaN HEMT transistor M 5 The source of the GaN HEMT transistor M 4The gate is connected through the inductor L g4 and voltage source V g4 Bias, GaN HEMT transistor M 5 The gate is connected through the inductor L g5 and voltage source V g5 Bias.

[0067] The output matching network consists of capacitor C 4 、Inductance L L 、Inductance L 4 and voltage source V mul Composition. Capacitor C 4 One end is connected to load R L The other end is connected to the GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The drain inductor L mul One end is connected to a GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The other end is connected to the voltage source V mul , inductance L 4 One end is connected to a GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The drain terminal is connected to ground.

[0068] Further integration Figure 3 The principle of the circuit of the first specific embodiment of the present invention is described as follows:

[0069] GaN HEMT transistor M 1 , capacitor C 1 , capacitor C d1 , capacitor C g1 、Inductance L d1 、Inductance L g1 , voltage source V g1 The oscillation circuit composed of the voltage source AVDD and the capacitor C 0 、GaN HEMT transistor M 2 、GaN HEMT transistor M 3 、GaN HEMT transistor M 31 、Inductance L g2 、Inductance L g3 、Inductance L g31 、Inductance L ctrl , voltage source V g2 , voltage source V g3 , voltage source V g31 and voltage source V ctrl The variable resistors composed of the two components generate an oscillation signal. 2、GaN HEMT transistor M 3 、GaN HEMT transistor M 31 It works in the linear region, not the saturation region, so its resistance value can vary with the voltage source V ctrl The oscillation frequency changes with the change of resistance. The transfer function of the system shows that when the resistance value changes, the oscillation frequency will change. And because the change range of a single resistor is relatively small, three GaN HEMTs are used.

[0070] By capacitor C 2 and inductor L 0 The matching network is formed to reduce the loss of the oscillation signal to the next-stage balun. The circuit structure is not unique and depends on the actual situation.

[0071] By coil L pri and coil L sec The balun composed of the single-ended output signal is converted into a differential signal with a double-ended output. The differential signals are equal in magnitude and 180° in phase. 4 、GaN HEMT transistor M 5 、Inductance L g4 、Inductance L g5 , voltage source V g4 and voltage source V g5 The frequency doubler composed of the two adds the differential signals, cancels out the fundamental signal, and doubles the amplitude of the second harmonic signal; the capacitor C 4 、Inductance L L 、Inductance L 4 and voltage source V mul The output matching network is used to reduce the loss of the output signal of the frequency multiplier to the load. The structure is not unique and depends on the actual situation.

[0072] The beneficial effect of the first specific embodiment of the present invention is that a high-frequency, high-output-power voltage-controlled oscillator is realized by using GaN HEMT, and the devices used can be realized under the current process, thereby solving the problem that a varactor diode cannot be used to tune the frequency under the current GaN HEMT process. Specific embodiment 2:

[0074] The invention provides a GaN HEMT high-frequency high-power voltage-controlled oscillator without using a varactor diode, comprising: an oscillation loop, a matching circuit, a balun, a frequency doubler and an output matching network.

[0075] The oscillation circuit consists of the GaN HEMT transistor M 1 , capacitor C 1 , capacitor C d1 , capacitor C g1 、Inductance Ld1 、Inductance L g1 , voltage source V g1 and voltage source AVDD.

[0076] GaN HEMT transistor M 1 The drain of d1 Connect to voltage source AVDD and pass capacitor C 1 Feedback to the gate; the gate passes through the inductor L g1 and voltage source V g1 Bias, source grounded; bypass capacitor C d1 One end connected to L d1 , the other end is grounded; bypass capacitor C g1 One end connected to L g1 , and the other end is grounded.

[0077] The matching network consists of capacitor C 2 and inductor L 0 Composition, capacitor C 2 One end is connected to a GaN HEMT transistor M 2 、GaN HEMT transistor M 3 、GaN HEMT transistor M 31 The other end is connected to the inductor L 0 , inductance L 0 The other end is grounded.

[0078] The balun consists of a coil L pri and coil L sec The coil L is composed of two coils and is anti-phase coupled. pri One end is connected to the output end of the matching circuit, and the other end is grounded. sec The two ends are respectively connected to the two ends of the doubler.

[0079] The frequency doubler is composed of GaN HEMT transistor M 4 、GaN HEMT transistor M 5 、Inductance L g4 、Inductance L g5 , voltage source V g4 and voltage source V g5 Composition. GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The drain is directly connected to the voltage source V mul Power supply, GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The gates of the GaN HEMT transistors M are connected to the two output terminals of the balun. 4 、GaN HEMT transistor M 5The source of the GaN HEMT transistor M 4 The gate is connected through the inductor L g4 and voltage source V g4 Bias, GaN HEMT transistor M 5 The gate is connected through the inductor L g5 and voltage source V g5 Bias.

[0080] The output matching network consists of capacitor C 4 、Inductance L L 、Inductance L 4 and voltage source V mul Composition. Capacitor C 4 One end is connected to load R L The other end is connected to the GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The drain inductor L mul One end is connected to a GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The other end is connected to the voltage source V mul , inductance L 4 One end is connected to a GaN HEMT transistor M 4 、GaN HEMT transistor M 5 The drain terminal is connected to ground.

[0081] Further integration Figure 4 The principle of the circuit of the second specific embodiment of the present invention is described as follows:

[0082] In this example, the GaN HEMT transistor M of the doubler needs to be 4 、GaN HEMT transistor M 5 Biased at the junction of the linear region and the saturation region, so that the voltage source V mul When the GaN HEMT transistor M is changed, 4 、GaN HEMT transistor M 5 AC impedance, so from the AC point of view, GaN HEMT transistor M 1 , capacitor C 1 , capacitor C d1 , capacitor C g1 、Inductance L d1 、Inductance L g1 , voltage source V g1 The oscillation loop formed by the voltage source AVDD still contains a variable resistor, so the voltage source V mul By changing, the resistance of the oscillation circuit can be changed, thereby achieving a change in frequency.

[0083] By capacitor C 2 and inductor L 0 The matching network is formed to reduce the loss of the oscillation signal to the next-stage balun. The circuit structure is not unique and depends on the actual situation.

[0084] By coil L pri and coil L sec The balun composed of the single-ended output signal is converted into a differential signal with a double-ended output. The differential signals are equal in magnitude and 180° in phase. 4 、GaN HEMT transistor M 5 、Inductance L g4 、Inductance L g5 , voltage source V g4 and voltage source V g5 The frequency doubler composed of the two adds the differential signals, cancels out the fundamental signal, and doubles the amplitude of the second harmonic signal; the capacitor C 4 、Inductance L L 、Inductance L 4 and voltage source V mul The output matching network is used to reduce the loss of the output signal of the frequency multiplier to the load. The structure is not unique and depends on the actual situation.

[0085] The beneficial effect of the second specific embodiment of the present invention is that a high-frequency, high-output power voltage-controlled oscillator is realized by using GaN HEMT, and the devices used can be realized under the current process, solving the problem that the variable capacitance diode cannot be used to tune the frequency under the current GaN HEMT process. At the same time, compared with the second specific embodiment, three GaN HEMTs are omitted, saving power consumption and wafer production costs.

[0086] The contents of the above method embodiments are all applicable to the present system embodiments. The functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0087] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A high-frequency and high-power voltage-controlled oscillator based on GaN HEMT, characterized in that: It includes an oscillating circuit, a variable resistor circuit, a matching circuit, a balun circuit, a frequency doubler circuit and an output matching network circuit, wherein the oscillating circuit, the variable resistor circuit, the matching circuit, the balun circuit, the frequency doubler circuit and the output matching network circuit are connected in sequence, wherein: The oscillation circuit is used to generate an oscillation signal; The variable resistance circuit is used to adjust the frequency of the oscillation signal to obtain an adjusted oscillation signal; The matching circuit is used to reduce the power loss of the adjusted oscillation signal to the next-stage balun circuit to obtain a single-ended oscillation signal with low power loss; The balun circuit is used to convert the low-power-loss single-ended oscillation signal to obtain a differential signal output at both ends; The frequency doubler circuit is used to perform addition processing on the differential signal output from both ends to obtain a second harmonic oscillation signal; The output matching network circuit is used to reduce the loss of the second harmonic oscillation signal to the output load, thereby obtaining a high-frequency and high-power oscillation signal.

2. A high-frequency and high-power voltage-controlled oscillator based on GaN HEMT according to claim 1, characterized in that: The oscillation circuit specifically includes a first GaN HEMT transistor, a first capacitor, a second capacitor, a first inductor, a second inductor and a first voltage source, wherein the gate of the first GaN HEMT transistor, the first end of the first capacitor and the first end of the second inductor are connected, the second end of the second inductor and the first end of the second capacitor are connected to the positive terminal of the first voltage source, the second end of the first capacitor, the drain of the first GaN HEMT transistor and the second end of the first inductor are connected to the variable resistance circuit, the first end of the first inductor is connected to a high level, and the source of the first GaN HEMT transistor, the second end of the second capacitor and the negative terminal of the first voltage source are all grounded.

3. A high-frequency and high-power voltage-controlled oscillator based on GaN HEMT according to claim 2, characterized in that: The variable resistance circuit specifically includes a third capacitor, a second GaN HEMT transistor, a third GaN HEMT transistor, a third inductor, a fourth inductor, a fifth inductor, a second voltage source, a third voltage source and a fourth voltage source, wherein a first end of the third capacitor is connected to the oscillation circuit, a second end of the third capacitor, a drain of the second GaN HEMT transistor, a drain of the third GaN HEMT transistor and a first end of the fifth inductor are connected to the matching circuit, a gate of the second GaN HEMT transistor is connected to a second end of the fourth inductor, a first end of the fourth inductor is connected to a positive end of the third voltage source, a gate of the third GaN HEMT transistor is connected to a first end of the third inductor, a second end of the third inductor is connected to a positive end of the second voltage source, a second end of the fifth inductor is connected to a positive end of the fourth voltage source, and a negative end of the second voltage source, a negative end of the third voltage source, a negative end of the fourth voltage source, a source of the second GaN HEMT transistor and a source of the third GaN HEMT transistor are all grounded.

4. A high-frequency and high-power voltage-controlled oscillator based on GaN HEMT according to claim 3, characterized in that: The matching circuit specifically includes a fourth capacitor and a fifth capacitor, wherein a first end of the fourth capacitor is connected to the variable resistance circuit, a second end of the fourth capacitor and a second end of the fifth capacitor are connected to the balun circuit, and a first end of the fifth capacitor is grounded.

5. A high-frequency and high-power voltage-controlled oscillator based on GaN HEMT according to claim 4, characterized in that: The balun circuit specifically includes a first coil and a second coil, wherein the first coil and the second coil are anti-coupled, a first end of the first coil is connected to the matching circuit, a second end of the first coil is grounded, and a first end of the second coil and a second end of the second coil are both connected to the doubler circuit.

6. A high-frequency and high-power voltage-controlled oscillator based on GaN HEMT according to claim 5, characterized in that: The frequency doubler circuit specifically includes a fourth GaN HEMT transistor, a fifth GaN HEMT transistor, a sixth inductor, a seventh inductor, a fifth voltage source and a sixth voltage source, wherein a gate of the fourth GaN HEMT transistor and a first end of the sixth inductor are connected to the balun circuit, a second end of the sixth inductor is connected to a positive terminal of the fifth voltage source, a gate of the fifth GaN HEMT transistor and a first end of the seventh inductor are connected to the balun circuit, a second end of the seventh inductor is connected to a positive terminal of the sixth voltage source, a drain of the fourth GaN HEMT transistor and a drain of the fifth GaN HEMT transistor are connected to the output matching network circuit, and a source of the fourth GaN HEMT transistor, a source of the fifth GaN HEMT transistor, a negative terminal of the fifth voltage source and a negative terminal of the sixth voltage source are all grounded.

7. A high-frequency and high-power voltage-controlled oscillator based on GaN HEMT according to claim 6, characterized in that: The output matching network circuit specifically includes a sixth capacitor, a seventh inductor, an eighth inductor, a first resistor and a seventh voltage source, wherein the first end of the sixth capacitor and the first end of the seventh inductor are connected to the doubler circuit, the second end of the sixth capacitor and the first end of the eighth inductor are connected to the first end of the first resistor, the second end of the seventh inductor is connected to the positive terminal of the seventh voltage source, and the second end of the first resistor, the second end of the eighth inductor and the negative terminal of the seventh voltage source are all grounded.

8. A control method for a high-frequency and high-power voltage-controlled oscillator based on GaN HEMT, characterized in that: The following steps are involved: Acquiring an oscillation signal and adjusting the frequency of the oscillation signal to obtain an adjusted oscillation signal; Reducing the power loss of the adjusted oscillation signal to obtain a single-ended oscillation signal with low power loss; Converting the low-power-loss single-ended oscillation signal to obtain a double-ended output differential signal; Adding the differential signals output from both ends to obtain a second harmonic oscillation signal; The loss of the second harmonic oscillation signal to the output load is reduced to obtain a high-frequency and high-power oscillation signal.

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